De-interlacing method and controller thereof

ABSTRACT

A de-interlacing method and controller is provided. The de-interlacing method includes steps of de-interlacing based on an i th  odd input pixel row of an odd field and an i th  even input pixel row of an even field to generate an i th  odd output pixel row, where i is a natural number; de-interlacing based on the i th  even input pixel row and an (i+1) th  odd input pixel row of the odd field to generate an i th  even output pixel row; and adjusting i and repeating the above steps to generate a complete interpolated frame.

CROSS REFERENCE TO RELATED PATENT APPLICATION

This patent application is based on a Taiwan, R.O.C. patent applicationNo. 097151862 filed on Dec. 31, 2008.

FIELD OF THE INVENTION

The present invention relates to a de-interlacing controller and method,and more particularly, to a double frame rate de-interlacing controllerand method.

BACKGROUND OF THE INVENTION

Double frame rate liquid crystal display (LCD) televisions having aframe rate, or a frame frequency, e.g. 120 Hz, are now available to themarket. Such LCD televisions operating at a frame rate of 120 Hzeffectively overcomes the flicker issue of a conventional LCD televisionoperating at a frame rate of 60 Hz. Using current techniques, uponreceiving an input image, e.g. 60 Hz, a conventional double frame ratede-interfacing television duplicates each frame of the input image andplaces the same between each frame and a next frame to achieve thedouble frame rate, e.g. 120 Hz.

However, as the input image contains an object moving with a high speed,a residual image of the moving object is resulted in a display image dueto the conventional double frame rate de-interlacing televisionconsecutively playing two identical frames. In view of such issue, it isa vital task of the industry to provide a solution for improving theresidual image of the display image of the conventional double framerate de-interlacing television while also taking manufacturing costsinto consideration.

SUMMARY OF THE INVENTION

Therefore, it is one object of the invention to provide a low-costdouble frame rate de-interlacing controller and a method thereof forimproving the residual image.

The present invention discloses a double frame rate de-interlacingmethod, comprising steps of generating a plurality of de-interlacedframes by performing an EODI operation based on an odd field and an evenfield that are temporally adjacent; and adaptively blending thede-interlaced frames with the odd field and the even field to generate aplurality of interpolated frames.

The present invention further discloses a double frame ratede-interlacing controller, for generating an output image in response toan input image, the input image comprising an odd field and an evenfield, the output image comprising a first interpolated frame, thede-interlacing controller comprising: a memory, a control circuit, ade-interlace engine and a blender. The memory receives and stors the oddfield and the even field. The control circuit reads and outputs ani^(th) odd input pixel row of the odd field, an (i+1)^(th) odd inputpixel row of the odd field and an i^(th) even input pixel row of theeven field. The de-interlace engine de-interlaces based on the i^(th)odd input pixel row and the i^(th) even input pixel row to generate afirst pixel row, and performs the EODI operation based on the (i+1)^(th)odd input pixel row and the i^(th) even input pixel row to generate asecond pixel row. The first and second pixel rows are assigned as ani^(th) odd output pixel row and an i^(th) even output pixel row of thefirst interpolated frame, respectively. The blender determines a firstweight parameter and a second weight parameter for the first pixel rowand the i^(th) odd input pixel row, to generate the i^(th) odd outputpixel row of the first interpolated frame and determines a third weightparameter and a fourth weight parameter for the second pixel row and thei^(th) even input pixel row, to generate the i^(th) even output pixelrow of the first interpolated frame.

The present invention further discloses a double frame ratede-interlacing method, for generating an output image in response to aninput image, the input image comprising an odd field and an even field,the output image comprising a first interpolated frame, thede-interlacing method comprising steps of: generating an i^(th) oddoutput pixel row of the first interpolated frame by performing an edgeoriented de-interlacing (EODI) operation based on an i^(th) odd inputpixel row of the odd field and the i^(th) even input pixel row of theeven field, where i is a natural number; generating an i^(th) evenoutput pixel row of the first interpolated frame by performing the EODIoperation based on the i^(th) even input pixel row and an (i+1)^(th) oddinput pixel row of the odd field; and adjusting i and repeating theabove steps to obtain all odd and even output pixel rows of the firstinterpolated frame.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more readily apparent to thoseordinarily skilled in the art after reviewing the following detaileddescription and accompanying drawings, in which:

FIG. 1 is a schematic diagram of an input image and an output image of ade-interlacing controller according to one embodiment of the invention;

FIGS. 2A to 2E are block diagrams of a double frame rate de-interlacingcontroller according to a first embodiment of the invention;

FIG. 3A is a partial flowchart of a double frame rate de-interlacingoperation method according to the first embodiment of the invention;

FIG. 3B is a partial flowchart of a double frame rate de-interlacingoperation method according to the first embodiment of the invention;

FIG. 3C is a partial flowchart of a double frame rate de-interlacingoperation method according to the first embodiment of the invention;

FIG. 3D is a partial flowchart of a double frame rate de-interlacingoperation method according to the first embodiment of the invention;

FIG. 4 is a schematic diagram illustrating operations of an EODI engineaccording to the first embodiment of the invention;

FIGS. 5A to 5E are block diagrams of a double frame rate de-interlacingcontroller according to a second embodiment of the invention;

FIG. 6 is a block diagram of a blender according to the secondembodiment of the invention;

FIG. 7A is a partial flowchart of a double frame rate de-interlacingoperation method according to the second embodiment of the invention;

FIG. 7B is a partial flowchart of a double frame rate de-interlacingoperation method according to the second embodiment of the invention;

FIG. 7C is a partial flowchart of a double frame rate de-interlacingoperation method according to the second embodiment of the invention;

FIG. 7D is a partial flowchart of a double frame rate de-interlacingoperation method according to the second embodiment of the invention;

FIG. 7E is a partial flowchart of a double frame rate de-interlacingoperation method according to the second embodiment of the invention;

FIG. 7F is a partial flowchart of a double frame rate de-interlacingoperation method according to the second embodiment of the invention;

FIG. 8A is a schematic diagram of an interpolated frame “Frame”according to the second embodiment of the invention;

FIG. 8B is a schematic diagram of an interpolated frame “Pre-Frame”according to the second embodiment of the invention; and

FIG. 9 is a double frame rate de-interlacing method according to onepreferred embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In one embodiment, a de-interlacing method generates output images inresponse to input images. The input image comprises an odd field and aneven field, and the output image comprises an interpolated frame. Thede-interlacing method, at first, perform an edge oriented de-interlacing(EODI) operation based on an i^(th) odd input pixel row of the odd fieldand an i^(th) even input pixel row of the even field, an i^(th) oddoutput pixel row of the interpolated frame is generated, where i is anatural number. Then, by performing an EDOI operation based on thei^(th) even input pixel row of the even field and an (i+1)^(th) oddinput pixel row of the odd field, an i^(th) even output pixel row isgenerated. The value of i is incremented and the above steps arerepeated to obtain all odd and even output pixel rows of theinterpolated frame.

FIG. 1 shows a schematic diagram of an input image and an output imageusing the de-interlacing controller according to the embodiment. Aninput image Ii is an interlaced image. An odd field includes pixel datacorresponding to odd scan lines, and an even field includes pixel datacorresponding to even scan lines. In this embodiment, the de-interlacingcontroller performs double frame rate de-interlacing on the input imageIi to generate a progressive output image Io. In the followingdescription, how the de-interlacing controller according to oneembodiment generates frames Fm[t−1] to Fm[t+2] according to the fieldscorresponding to the input image Ii shall be discussed, wherein t is anatural number greater than 1.

In the first embodiment, the de-interlacing controller generates pixeldata of the interpolated frames Fm[t−1] to Fm[t+2] by performing EODIbased on pixel data of an odd field Fd[s] and an even field Fd[s+1].FIG. 2E shows a block diagram of a de-interlacing controller accordingto the first embodiment of the invention. A de-interlacing controller 10comprises a memory 12, a control circuit 14 and an EODI engine 16. Thecontrol circuit 14 is coupled to the memory 12, and the EODI engine 16is coupled to the control circuit 14. For example, the memory 12 is adynamic random access memory (DRAM), for storing pixel rows of aplurality of odd fields and even fields. For example, when performingoperations for generating the frames Fm[t−1] to Fm[t+1], the memory 12stores at least pixel rows of the odd field Fd[s] and the even fieldFd[s+1]; when performing operations for generating the frame Fd[t+2],the memory 12 stores at least pixel rows of the even field Fd[s+1] andan odd field Fd[s+2].

The control circuit 14 reads pixel rows of the odd and even fieldsstored in the memory 12, and provides the same to the EODI engine 16 togenerate interpolated frames. Operations of the EODI engine 16 forgenerating the interpolated frames Fm[t−1] to Fm[t+2] shall be discussedbelow. In the following section, i^(th) odd pixel rows Lo[t−1]o(i),Lo[t]o(i), Lo[t+1]o(i) and Lo[t+2]o(i) of the frames Fm[t−1] to Fm[t+2]shall be used for illustrating operations of the odd pixel rows of theframes Fm[t−1] to Fm[t+2], respectively; i^(th) even pixel rowsLo[t−1]e(i), Lo[t]e(i), Lo[t+1]e(i) and Lo[t+2]e(i) of the framesFm[t−1] to Fm[t+2] shall be used for illustrating operations of the evenpixel rows of the frames Fm[t−1] to Fm[t+2], respectively; where i is anatural number smaller than or equal to N.

Referring to FIGS. 3A, 2A and 1, during the interpolation operation forgenerating the frame Fm[t−1], the control circuit 14 accesses the memory12 to obtain input pixel rows Li[s]o(1) to Li[s]o(N) of the odd fieldFd[s], where N is a natural number greater than 1. FIG. 3A shows apartial flowchart of the de-interlacing method according to the firstembodiment. In FIG. 2A, only the input pixel rows Li[s]o(i) andLi[s]o(i+1) are depicted for illustration. In Step (d), the controlcircuit 14 applies the input pixel row Li[s]o(i) as the output pixel rowLo[t−1]o(i). In Step (e), the control circuit 14 provides the inputpixel rows Li[s]o(i) and Li[s]o(i+1) to the EODI engine 16, which thengenerates the output pixel row Lo[t−1]e(i) of the frame Fm[t−1]. In Step(f), the de-interlacing controller 10 adjusts i to obtain all the pixelrows of the frame Fm[t−1] by interpolation.

With reference to FIGS. 3B, 2B and 1, during the interpolation operationfor generating the frame Fm[t], the control circuit 14 accesses thememory 12 to obtain input pixel rows Li[s]o(1) to Li[s]o(N) of the oddfield Fd[s], and the input pixel rows Li[s+1]e(1) to Li[s+1]e(N) of theeven field Fd[s+1]. FIG. 3B shows a partial flowchart of thede-interlacing method according to this embodiment. In FIG. 2B, only theinput pixel rows Li[s]o(i), Li[s]o(i+1) and Li[s+1]e(i) are depicted forillustration. In Step (a), the control circuit 14 provides the inputpixel rows Li[s]o(i) and Li[s+1]e(i) to the EODI engine 16, which thengenerates the output pixel row Lo[t]o(i) of the frame Fm[t]. In Step(b), the control circuit 14 further provides the input pixel rowLi[s+1]e(i) and Li[s]o(i+1) to the EODI engine 16, which then generatesthe output pixel row Lo[t]e(i) of the frame Fm[t]. In Step (c), thede-interlacing controller 10 adjusts i to obtain all the pixel rows ofthe frame Fm[t] by interpolation.

With reference to FIGS. 3C, 2C and 1, during the interpolation operationfor generating the frame Fm[t+1], the control circuit 14 accesses thememory 12 to obtain the input pixel rows Li[s+1]e(1) to Li[s+1]e(N) ofthe even field Fd[s+1]. FIG. 3C shows a partial flowchart of thede-interlacing method according to this embodiment. In FIG. 2C, only theinput pixel rows Li[s+1]e(i) and Li[s+1]e(i+1) are depicted forillustration. In Step (g), the control circuit 14 provides the inputpixel rows Li[s+1]e(i) and Li[s+1]e(i+1) to the EODI engine 16, whichthen generates the output pixel row Lo[t+1]o(i) of the frame Fm[t+1]. InStep (h), the control circuit 14 applies the input pixel row Li[s+1]e(i)as the output pixel row Lo[t+1]e(i). In Step (i), the de-interlacingcontroller 10 adjusts i to obtain all the pixel rows of the frameFm[t+1] by interpolation.

With reference to FIGS. 3D, 2D and 1, during the interpolation operationfor generating the frame Fm[t+2], the control circuit 14 accesses thememory 12 to obtain the input pixel rows Li[s+1]e(1) to Li[s+1]e(N) ofthe even field Fd[s+1], and the input pixel rows Li[s+2]o(1) toLi[s+2]o(N) of the odd field Fd[s+2] (not shown). FIG. 3D shows apartial flowchart of the de-interlacing method according to thisembodiment. In FIG. 2D, only the input pixel rows Li[s+2]o(i),Li[s+2]o(i+1) and Li[s+1]e(i) are depicted for illustration. In Step(j), the control circuit 14 provides the input pixel rows Li[s+2]o(i)and Li[s+1]e(i) to the EODI engine 16, which then generates the outputpixel row Lo[t+2]o(i) of the frame Fm[t+2]. In Step (k), the controlcircuit 14 provides the input pixel rows Li[s+2]o(i+1) and Li[s+1]e(i)to the EODI engine 16, which then generates the output pixel rowLo[t+2]e(i) of the frame Fm[t+2]. In Step (1), the de-interlacingcontroller 10 adjusts i to obtain all the pixel rows of the frameFm[t+2] by interpolation.

FIG. 4 shows a schematic diagram illustrating operations of an EODIengine 16 according to one preferred embodiment of the invention. TheEODI engine 16 receives pixel rows LP1 and LP2 to accordingly generatean interpolated pixel row LP3, which includes pixel data P3(1) to P3(y).How the EODI engine 16 generates each of the pixel data P3(1) to P3(y)is substantially the same. Operations of the EODI engine 16 forgenerating the interpolated pixel data P3(x) shall be discussed below,where y is a natural number greater than 1, and x is a natural numbersmaller or equal to y.

An EODI operation comprises the following steps. According to aplurality of direction indices, a plurality of pixel data of the pixelrow LP1 are mapped to a plurality of pixel data of the pixel row LP2.For example, a direction index D includes {−1, −1, 0, 1, 2}, accordingto which pixel data P1(x+2) to P1(x−2) of the pixel row LP1 are mappedto pixel data P2(x−2) to P3(x+2) of the pixel row LP2, respectively.

Next, the pixel data P1(x−2) to P1(x+2) mapped by the direction index Dincluding values from −2 to 2, is centrally divided into correspondinglarge blocks Ma(−2) to Ma(2). Pixel data P2(x−2) to P2(x+2) mapped bythe direction index D including values from −2 to 2, is centrallydivided into corresponding large blocks Mb(−2) to Mb(2). For example,each of the large blocks Ma(−2) to Ma(2), and Mb(−2) to Mb(2) includesthree horizontal pixels. Block matching is then performed oncorresponding large blocks, e.g., Ma(D) and Mb(D), to obtain acorresponding block difference Diff(D), where D is −2 to 2. For example,a block difference Diff(−2) is obtained through the equation below:Diff(−2)=|P1(x−1)−P2(x+1)|+|P1(x−2)−P2(x+2)|+|P1(x−3)−P2(x+3)|

For example, a smallest block difference corresponding to the directionindex D is determined as a detection direction. Being a smallest blockdifference among the block differences Diff(−2) to Diff(2), the blockdifference Diff(−2) is determined as the detection direction.Interpolation is then performed based on the pixel data P1(x−2) andP2(x+2) corresponding to the detection direction to obtain pixel dataP3(x).

In the foregoing embodiment, operations of the de-interlacing controller10 for generating the frames Fm[t−1] to Fm[t+1] based on the odd fieldFd[s] and the even field Fd[s+1], and the frame Fm[t+2] based on the oddfield Fd[s+2] and the even field Fd[s+1] are illustrated as an example.To those skilled in the related art, it can be understood how all framesare generated.

The de-interlacing controller 10 according to this embodiment generatesfour interpolated frames based on the odd and even fields utilizing theEODI engine. Therefore, compared to a conventional de-interlacing systemthat directly displays two identical first frames as double frame ratedisplay, the de-interlacing controller according to this embodimenteffectively overcomes the issue of residual image.

FIG. 5E shows a block diagram of the de-interlacing controller 20according to the second embodiment of the invention. The de-interlacingcontroller 20 according to the second embodiment utilizes an EODI engineas well as a blender, by double frame rate interpolation, to obtainimage data of the frames Fm[t−1] to Fm[t+2] with reference to imagemotion of the input image Ii.

One main difference between a de-interlacing controller 20 according tothe second embodiment and the de-interlacing controller 10 according tothe first embodiment lies in a memory control circuit 24 and a blender28 according to the second embodiment. The blender 28, coupled to anEODI engine 26 and a control circuit 24, references an image motionfactor M of the input image Ii, and generates an interpolated outputpixel row Lout based on a pixel row generated by the EODI engine 26 andan input pixel row Lx2 provided by the control circuit 24.

FIG. 6 shows a block diagram of the blender 28. The blender 28determines weights of the pixel rows Lx1 and Lx2 according to the motionfactor M, and blends the same to generate an output pixel row Lout. Forexample, the blender 28 blends to generate an output pixel row Loutaccording to the following equation:Lout=Lx1xM+Lx2x(1−M)

Detailed descriptions on operations of the de-interlacing controller 20for generating the interpolated frames Fm[t−1] to Fm[t+2] shall be givenbelow. In the following section, i′^(th) odd pixel rows Lo[t−1]o(i)′,Lo[t]o(i′), Lo[t+1]o(i′) and Lo[t+2]o(i′) of the frames Fm[t−1] toFm[t+2], respectively, shall be used for illustrating operations of theodd pixel rows of the frames Fm[t−1] to Fm[t+2], respectively. I′^(th)even pixel rows Lo[t−1]e(i′), Lo[t]e(i′), Lo[t+1]e(i′) and Lo[t+2]e(i′)of the frames Fm[t−1] to Fm[t+2], respectively, shall be used forillustrating operations of the even pixel rows of the frames Fm[t−1] toFm[t+2], respectively; where i′ is a natural number smaller than orequal to N.

Referring to FIGS. 7A, 5A and 1, a de-interlacing method according tothe second embodiment differs from the embodiment shown in FIG. 3A thatStep (e) comprises Steps (e1) to (e3). In Step (e1), the EODI engine 26generates the pixel row Lx1 based on the input pixel rows Li[s]o(i′+1)and Li[s]o(i′). Operations of the EODI engine 26 based on input data areidentical to those of the EODI engine 16, and shall not be unnecessarilyfurther described. In Step (e2), the control circuit 24 accesses theinput pixel row Li[s+1]e(i′) stored in the memory 22 to serve as thepixel row Lx2 to the blender 28.

In Step (e3), according to motion factors M and (1−M), the blender 28determines weights of the pixel rows Lx1 and Lx2, respectively, andblends the same to generate an output pixel row Lout. The output pixelrow Lout is outputted as the output pixel row Lo[t−1]e(i′) of the frameFm[t−1].

With reference to FIGS. 7B, 7C, 5B and 1, the de-interlacing methodaccording to the second embodiment differs from the embodiment in FIG.3B that Step (a) comprises Steps (a1) to (a3), and Step (b) comprisesSteps (b1) to (b3). In Step (a1), the EODI engine 26 generates a pixelrow Lx1(t 1) based on the pixel rows Li[s]o(i′) and Li[s+1]e(i′). InStep (a2), the control circuit 24 provides the input pixel rowLi[s]o(i′) as a pixel row Lx2(t 1) to the blender 28. In Step (a3),according to the motion factor M, the pixel rows Lx1(t 1) and Lx2(t 1),a pixel row Lout is generated and outputted as the output pixel rowLo[t]o(i′).

In Step (b1), the EODI engine 26 generates a pixel row Lx1(t 2) based onthe pixel rows Li[s+1]e(i′) and Li[s]o(i′+1). In Step (b2), the controlcircuit 24 provides the input pixel row Li[s+1]e(i′) as a pixel rowLx2(t 2) to the blender 28. In Step (b3), according to the motion factorM, the pixel rows Lx1(t 2) and Lx2(t 2), a pixel row Lout is generatedand outputted as the output pixel row Lo[t]e(i′).

With reference to FIGS. 7D, 5C, and 1, the de-interlacing methodaccording to the second embodiment differs from the embodiment in FIG.3C that Step (g) comprises Steps (g1) to (g3). In Step (g1), the EODIengine 26 generates the pixel row Lx1 based on the pixel rowsLi[s+1]e(i′) and Li[s+1]e(i′+1). In Step (g2), the control circuit 24provides the input pixel row Li[s+2]o(i′) as the pixel row Lx2 to theblender 28. In Step (g3), according to the motion factor M, the pixelrows Lx1 and Lx2, a pixel row Lout is generated and outputted as theoutput pixel row Lo[t+1]o(i′).

With reference to FIGS. 7E, 7F, 5D and 1, the de-interlacing methodaccording to the second embodiment differs from the embodiment in FIG.3D that Step (j) comprises Steps (j1) to (j3), and Step (k) comprisesSteps (k1) to (k3). In Step (1), the EODI engine 26 generates a pixelrow Lx1(t 3) based on the pixel rows Li[s+2]o(i′) and Li[s+1]e(i′). InStep (j2), the control circuit 24 provides the input pixel rowLi[s+2]o(i′) as a pixel row Lx2(t 3) to the blender 28. In Step (j3),according to the motion factor M, the pixel rows Lx1(t 3) and Lx2(t 3),a pixel row Lout is generated and outputted as the output pixel rowLo[t+2]o(i′).

In Step (k1), the EODI engine 26 generates a pixel row Lx1(t 4) based onthe pixel rows Li[s+1]e(i′) and Li[s+2]o(i′+1). In Step (k2), thecontrol circuit 24 provides the input pixel row Li[s+1]e(i′) as a pixelrow Lx2(t 4) to the blender 28. In Step (k3), according to the motionfactor M, the pixel rows Lx1(t 4) and Lx2(t 4), a pixel row Lout isgenerated and outputted as the output pixel row Lo[t+2]e(i′).

The de-interlacing controller 20 according to the second embodiment ofthe invention may utilize a motion estimation circuit (not shown) togenerate the motion factor M. For each of the pixel data generated bythe blender 28, corresponding to the output image Io, the motionestimation circuit correspondingly generates the motion factor M. Forexample, the motion estimation circuit determines a motion estimationregion and, from an x^(th) pixel row of the frame Fm[t−1], estimates ay^(th) pixel data P[t]o(x,y) corresponding to a motion factorM[t]o(x,y), where x is a natural number smaller than or equal to N.Further, in the foregoing odd and even fields, each pixel row includes Zpixel data, and y is a natural number smaller than or equal to Z.

Refer to FIGS. 8A and 8B showing schematic diagram of motion estimationoperations of the motion estimation circuit according to thisembodiment. The motion estimation circuit synthesizes a frame Frame froman odd field Fd[s] and an even field Fd[s+1], and synthesizes a framePre_Frame from an odd field Fd[s−2] and an even field Fd[s−1].

The motion estimation circuit then defines an area A in the frame Frame.For example, the region A includes pixel data Pr1 to Pr9. Wherein, thepixel data Pr1 to Pr3 are pixel data P[s+1]e(x,y−1), P[s+1]e(x,y) andP[s+1]e(x,y+1) of an input pixel row Li[s+1]e(x) of the even fieldFd[s+1]. The pixel data Pr4 to Pr6 are pixel data P[s]o(x,y−1),P[s]o(x,y) and P[s]o(x,y+1) of an input pixel row Li[s]o(x) of the oddfield Fd[s]. The pixel data Pr7 to Pr9 are pixel data P[s+1]e(x+1,y−1),P[s+1]e(x+1,y) and P[s+1]e(x+1,y+1) of an input pixel row Li[s+1]e(x+1)of the even field Fd[s+1].

Similarly, the estimation circuit defines an area B in the framePre_Frame. The region B includes pixel data Pre_Pr1 to Pre_Pr9. Thepixel data Pre_Pr1 to Pre_Pr3 are pixel data P[s−1]e(x,y−1),P[s−1]e(x,y) and P[s−1]e(x,y+1) of an input pixel row Li[s−1]e(x) of theeven field Fd[s−1]. The pixel data Pre_Pr4 to Pre_Pr6 are pixel dataP[s−2]o(x,y−1), P[s−2]o(x,y) and P[s−2]o(x,y+1) of an input pixel rowLi[s−2]o(x) of the odd field Fd[s−2]. The pixel data Pre_Pr7 to Pre_Pr9are pixel data P[s−1]e(x+1,y−1), P[s−1]e(x+1,y) and P[s−1]e(x+1,y+1) ofan input pixel row Li[s−1]e(x+1) of the even field Fd[s−1].

The following equation may be applied to generate the motion factorM[t]o(x,y) corresponding to the pixel P[t]o(x,y):

${{M\lbrack t\rbrack}{o( {x,y} )}} = \frac{\sum\limits_{j = 1}^{9}{{{Prj} - {Pre\_ Prj}}}}{Threshold}$

Operations for generating corresponding motion factors M forinterpolating other pixels of the frames Fm[t−1] to Fm[t+2] may beobtained similarly.

As mentioned, a conventional EODI engine is implemented to perform anEODI operation within a same field. Whereas, the EODI engine accordingto the embodiments of the invention generates interpolated double framerate frames based on corresponding original frames. Therefore, comparedto the conventional double frame rate de-interlace of the prior art withthe issue of residual image resulted from directly displaying twoidentical frames, the de-interlacing controller according to thisembodiment is not only low in cost but also has the advantage ofovercoming the issue of residual image.

In addition, the de-interlacing controller according to this embodimentapplies a blender to generate corresponding interpolated output imagewith reference to image motion degrees of the input image. Thus,utilizing the de-interlacing controller according to this embodiment,the various frames of the output image are interpolated with referenceto motion degrees of the input image to further enhance display quality.

FIG. 9 shows a double frame rate de-interlacing method according to onepreferred embodiment of the invention. In Step 910, based on temporallyadjacent odd and even fields, an EODI operation is performed to generatedouble frame rate de-interlaced frame. In Step 920, each of thede-interlaced frames is adaptively blended to generate an interpolatedde-interlaced frame. For example, according to an image motion factor,each of the de-interlaced frames is blended with the odd fields and theeven fields to generate de-interlaced frames. More specifically, theimage motion factor is determined by a target pixel row and a pluralityof spatially adjacent pixel rows of a plurality of temporally adjacentfields. For example, the image motion factor is associated with a sum ofan absolute difference of pixel data of a plurality of spatiallyadjacent pixel rows of a plurality of temporally adjacent fields.

To sum up, the present invention discloses a double frame ratede-interlacing method, comprising steps of generating a plurality ofde-interlaced frames by performing an EODI operation based on an oddfield and an even field that are temporally adjacent; and adaptivelyblending the de-interlaced frames with the odd field and the even fieldto generate a plurality of interpolated frames.

The present invention further discloses a double frame ratede-interlacing controller, for generating an output image in response toan input image, the input image comprising an odd field and an evenfield, the output image comprising a first interpolated frame, thede-interlacing controller comprising: a memory, a control circuit, ade-interlace engine and a blender. The memory receives and stors the oddfield and the even field. The control circuit reads and outputs ani^(th) odd input pixel row of the odd field, an (i+1)^(th) odd inputpixel row of the odd field and an i^(th) even input pixel row of theeven field. The de-interlace engine de-interlaces based on the i^(th)odd input pixel row and the i^(th) even input pixel row to generate afirst pixel row, and performs the EODI operation based on the (i+1)^(th)odd input pixel row and the i^(th) even input pixel row to generate asecond pixel row. The first and second pixel rows are assigned as ani^(th) odd output pixel row and an i^(th) even output pixel row of thefirst interpolated frame, respectively. The blender determines a firstweight parameter and a second weight parameter, e.g. derived from motionfactor M, for the first pixel row and the i^(th) odd input pixel row, togenerate the i^(th) odd output pixel row of the first interpolated frameand determines a third weight parameter and a fourth weight parameterfor the second pixel row and the i^(th) even input pixel row, togenerate the i^(th) even output pixel row of the first interpolatedframe.

The present invention further discloses a double frame ratede-interlacing method, for generating an output image in response to aninput image, the input image comprising an odd field and an even field,the output image comprising a first interpolated frame, thede-interlacing method comprising steps of: generating an i^(th) oddoutput pixel row of the first interpolated frame by performing an edgeoriented de-interlacing (EODI) operation based on an i^(th) odd inputpixel row of the odd field and the i^(th) even input pixel row of theeven field, where i is a natural number; generating an i^(th) evenoutput pixel row of the first interpolated frame by performing the EODIoperation based on the i^(th) even input pixel row and an (i+1)^(th) oddinput pixel row of the odd field; and adjusting i and repeating theabove steps to obtain all odd and even output pixel rows of the firstinterpolated frame.

While the invention has been described in terms of what is presentlyconsidered to be the most practical and preferred embodiments, it is tobe understood that the invention needs not to be limited to the aboveembodiments. On the contrary, it is intended to cover variousmodifications and similar arrangements included within the spirit andscope of the appended claims which are to be accorded with the broadestinterpretation so as to encompass all such modifications and similarstructures.

1. A double frame rate de-interlacing method, for generating an outputimage in response to an input image, the input image comprising an oddfield and an even field, the output image comprising a firstinterpolated frame, the de-interlacing method comprising steps of:generating an i^(th) odd output pixel row of the first interpolatedframe by de-interlacing based on an i^(th) input pixel row of the oddfield and the i^(th) input pixel row of the even field, where i is anatural number; generating an i^(th) even output pixel row of the firstinterpolated frame by de-interlacing based on the i^(th) input pixel rowof the even field and an (i+1)^(th) input pixel row of the odd field;and adjusting i and repeating the above steps to obtain all odd and evenoutput pixel rows of the first interpolated frame, wherein the step ofgenerating the i^(th) odd output pixel row of the first interpolatedframe further comprises steps of: generating a first pixel row byde-interlacing based on the i^(th) input pixel row of the odd field andi^(th) input pixel row of the even field; assigning the i^(th) inputpixel row of the odd field as a second pixel row; and determining afirst weight parameter and a second weight parameter for the first andsecond pixel rows, to generate the i^(th) odd output pixel row of thefirst interpolated frame, wherein a sum of the first and second weightparameters equals to 1, and the first and second weight parameters areassociated with a motion degree of the input image.
 2. The double framerate de-interlacing method as claimed in claim 1, wherein the step ofgenerating the i^(th) even output pixel row of the first interpolatedframe further comprises steps of: generating a first pixel row byde-interlacing based on the (i+1)^(th) input pixel row of the odd fieldand the i^(th) input pixel row of the even field; assigning the i^(th)input pixel row of the even field as a second pixel row; and determininga first weight parameter and a second weight parameter for the first andsecond pixel rows, to generate the i^(th) even output pixel row of thefirst interpolated frame.
 3. The double frame rate de-interlacing methodas claimed in claim 2, wherein a sum of the first and second weightparameters equals to 1, and the first and second weight parameters areassociated with a motion degree of the input image.
 4. The double framerate de-interlacing method as claimed in claim 1, further comprisingsteps of: assigning the i^(th) input pixel row of the odd field as ani^(th) odd output pixel row of a second interpolated frame; i^(th)generating an ^(th) even output pixel row of the second interpolatedframe by de-interlacing based on the i^(th) input pixel row of the oddfield and the (i+1)^(th) input pixel row of the odd field; and adjustingi and repeating the above steps to obtain all odd and even output pixelrows of the second interpolated frame.
 5. The double frame ratede-interlacing method as claimed in claim 4, wherein the step ofgenerating the i^(th) even output pixel row of the second interpolatedframe further comprises steps of: generating a first pixel row byde-interlacing based on the i^(th) and (i+1)^(th) input pixel rows ofthe odd field; assigning the i^(th) input pixel row of the even field asa second pixel row; and determining a first weight parameter and asecond weight parameter for the first and second pixel rows, to generatethe i^(th) even output pixel row of the second interpolated frame. 6.The double frame rate de-interlacing method as claimed in claim 5,wherein a sum of the first and second weight parameters equals to 1, andthe first and second weight parameters are associated with a motiondegree of the input image.
 7. The double frame rate de-interlacingmethod as claimed in claim 1, further comprising steps of: generating ani^(th) odd output pixel row of a third interpolated frame byde-interlacing based on the i^(th) input pixel row of the even field andan (i+1)^(th) input pixel row of the even field; assigning the i^(th)input pixel row of the even field as an i^(th) even output pixel row ofthe third interpolated frame; and adjusting i and repeating the abovesteps to obtain all odd and even output pixel rows of the thirdinterpolated frame.
 8. A double frame rate de-interlacing controller,for generating an output image in response to an input image, the inputimage comprising an odd field and an even field, the output imagecomprising a first interpolated frame, the de-interlacing controllercomprising: a memory for receiving and storing the odd field and theeven field; a control circuit for reading and outputting an i^(th) inputpixel row of the odd field, an (i+l)^(th) input pixel row of the oddfield and an i^(th) input pixel row of the even field, where i is anatural number; and a de-interlace engine for de-interlacing based onthe i^(th) input pixel row of the odd field and the i^(th) input pixelrow of the even field to generate a first pixel row, and de-interlacingbased on the (i+1)^(th) input pixel row of the odd field and the i^(th)input pixel row of the even field to generate a second pixel row; and ablender for determining a first weight parameter and a second weightparameter for the first pixel row and the i^(th) input pixel row of theodd field, to generate the i^(th) odd output pixel row of the firstinterpolated frame and determining a third weight parameter and a fourthweight parameter for the second pixel row and the i^(th) input pixel rowof the even field, to generate the i^(th) even output pixel row of thefirst interpolated frame; wherein, the first and second pixel rows areassigned as an i^(th) odd output pixel row and an i_(th) even outputpixel row of the first interpolated frame, respectively.
 9. The doubleframe rate de-interlacing controller as claimed in claim 8, wherein asum of the first and second weight parameters equals to 1, and the firstand second weight parameters are associated with a motion degree of theinput image; and a sum of the third and fourth weight parameters equalsto 1, and the third and fourth weight parameters are associated with amotion degree of the input image.
 10. The double frame ratede-interlacing controller as claimed in claim 8, wherein the i^(th)input pixel row of the odd field and the i^(th) even input pixel row ofthe even field are assigned as an i^(th) odd output pixel row of asecond interpolated frame and an i^(th) even output pixel row of a thirdinterpolated frame, respectively.
 11. The double frame ratede-interlacing controller as claimed in claim 10, wherein thede-interlace engine de-interlaces based on the i^(th) input pixel row ofthe odd field and the (i+1)^(th) input pixel row of the odd field togenerate a third pixel row, and de-interlaces based on the i^(th) inputpixel row of the even field and the (i-1)^(th) input pixel row of theeven filed to generate a fourth pixel row; wherein, the third and fourthpixel rows are assigned as an i^(th) even output pixel row of the secondinterpolated frame and an i^(th) odd output pixel row of the thirdinterpolated frame, respectively.